Biden slams Trump's dangerous NATO remarks

US President Joe Biden blasts comments about NATO by his likely 2024 election opponent, Donald Trump, calling the remarks "dangerous" and "un-American" and saying they raised the stakes for the US Congress to approve new funding to support Ukraine.

At the White House, the Democratic president criticised Trump's comment calling into question US willingness to support members of the Western defense alliance if they were attacked.

Biden said the comments by Trump, a Republican, made it more urgent that Congress pass his long-stalled funding request to support Ukraine's defense against Russia.

"The stakes were already high for American security before this bill was passed in the Senate last night," he said. "But in recent days, those stakes have risen. And that's because the former president has sent a dangerous, and shockingly, frankly un-American signal to the world."

On Saturday, Trump complained during a political rally in South Carolina about what he called "delinquent" payments by NATO members and recounted what he said was a past conversation with the head of "a big country" about a potential attack by Russia.

"No, I would not protect you. In fact, I would encourage them (Russia) to do whatever the hell they want. You gotta pay," Trump said he told the unnamed leader.

Biden said Trump's comments amounted to an invitation to Russia to invade US allies.

"Can you imagine a former president of the United States saying that? The whole world heard it. And the worst thing is he means it," he said. "No other president in our history has ever bowed down to a Russian dictator. Well, let me say this as clearly as I can: I never will."